section .text:
  global _start

_start:
  ;;; main() { }

hex2ascii:
  ; prelude
  push    ebp
  mov     ebp, esp

  ; stack: [ arg | return address | saved ebp ]
  ;           ^ ebp + 8  ^ ebp + 4    ^ ebp
  mov     eax, [ebp+8]    ; fetch argument from stack
  and     eax, 0x0F
  cmp     eax, 0xA
  jge     AthruF
  add     eax, '0'
  jmp     done
AthruF:
  sub     eax, 0xA
  add     eax, 'A'
done:
  leave
  ret                     ; return result in eax

printShort:
  ; prelude
  push  ebp
  mov   ebp, esp

  sub   esp, 8            ; make space for char ascii[] with word alignment
  mov   esi, ebp          ; set string address
  sub   esi, 8            ; esi = ebp - 8
  mov   [esi+4], byte '\n'; ascii[4] = '\n'

  ; stack: [ arg | return address | saved ebp | 3 padding bytes | ascii[] ]
  ;                                   ^ ebp
  mov   edx, [ebp+8]      ; load argument into edx

  and   edx, 0x0F         ; data & 0x0F
  push  edx               ; push for call
  call  hex2ascii         ; eax = hex2ascii(data & 0x0f)
  pop   edx               ; clean up stack
  mov   [esi+3], al       ; ascii[3] = (byte) eax
  shr   edx, 4            ; data >>= 4

  and   edx, 0x0f         ; data & 0x0F
  push  edx               ; push for call
  call  hex2ascii         ; eax = hex2ascii(data & 0x0f)
  pop   edx               ; clean up stack
  mov   [esi+2], al       ; ascii[2] = (byte) eax
  shr   edx, 4            ; data >>= 4

  and   edx, 0x0f         ; data & 0x0F
  push  edx               ; push for call
  call  hex2ascii         ; eax = hex2ascii(data & 0x0f)
  pop   edx               ; clean up stack
  mov   [esi+1], al       ; ascii[1] = (byte) eax
  shr   edx, 4            ; data >>= 4

  and   edx, 0x0f         ; data & 0x0F
  push  edx               ; push for call
  call  hex2ascii         ; eax = hex2ascii(data & 0x0f)
  pop   edx               ; clean up stack
  mov   [esi], al         ; ascii[0] = (byte) eax

  mov   eax, 4            ; syscall - write()
  mov   ebx, 1            ; set stdout
  mov   ecx, esi          ; set string address
  mov   edx, 5            ; print 5 bytes
  int   0x80

  leave
  ret

exit:
  mov     eax, 1
  int     80h